Ihave a 2006 MC LTand it seems that the rear window defog is inoperative. I have replaced the relay fuse type thing in the in hood fuse box and and checked the wire connections to the window on the right and left side and isstill not working. I have to blast the heat and point the vents toward the back. Anyone have this problem or know how to fix it?

Your 2006 may be different, but on my 2004 there's a fuse in the lower fuse block under the hood labelled "RT I/P #3" that controls the rear defogger and audio system. This sounds like the one you already checked.

There's also two things on the fuse block on the passenger side dash. Theres a fuse block behind an access panel on the side of the dash when you open the passenger door. On my 2004, this fuse panel has a circuit breaker in the lower right corner labelled, "REAR DEFOG BRKR". There's also a relay in the lower left corner labelled, "REAR DEFOG RELAY".

I just had the exact same thing happen to my 06 MC LT.. Took it up to the dealership (only cause its still under warranty) and they found that moisture had gotten into the fuse block inside the car and shorted out the wire (I believe it was #260 to be exact).. They replaced the whole thing for me because it was under warranty.

Just something to think about.. Even if you don't take it to a dealership, that should give you somewhere to start.

Yea that's whatI will most likelydo espically sinceI work at a chevy dealership. I had checked in the fuse box under the hood and replaced the relay/fuse andI checked the one in the cabin on thepassenger side near the floor and that one dosent evin have a fuse or anything that coresponds to a rear window defog. Hopefully mine will be covered, did they say what it would have costed you had it not been covered by warranty.

They didn't say how much it would cost if it wasn't under warranty.. Even on my paperwork, it shows all 0.00 for cost of items because it all says covered by warranty.

I got my xenon lights of of e-bay.. As strange as it sounds, I got them there almost a year ago.. Still wonderful as ever.. Well worth the money Used to have a pair in my 03 MC SS and when I got my 06 MC LT, I missed them for about a month.. What kind of sucked was that the connectors were just a fraction different.. The two prongs in the connector are like 1/8" wider or narrower (can't remember right now) than on the 03.